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Fencer Vulns
high 8.5

CVE-2021-39141 in the critical feed json

XStream is vulnerable to an Arbitrary Code Execution attack

published 2021-08-23 5 y ago modified 2026-10-07 32 d ago also GHSA-g5w6-mrj7-75h2 , EUVD-2021-1714

cvss
8.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
16.1%
EPSS 16.1% chance of exploitation in 30 days, percentile 96%
public exploits
0
none known, plus a Nuclei check

Summary

XStream is a simple library to serialize objects to XML and back again. In affected versions this vulnerability may allow a remote attacker to load and execute arbitrary code from a remote host only by manipulating the processed input stream. No user is affected, who followed the recommendation to setup XStream's security framework with a whitelist limited to the minimal required types. XStream 1.4.18 uses no longer a blacklist by default, since it cannot be secured for general purpose.

Patch / fix

  • maven com.thoughtworks.xstream:xstream 1.4.18
  • xstream xstream 1.4.18
  • libxstream-java Debian 14, Debian 13, Debian 12 1.4.18-1

debian advisories DEBIAN-CVE-2021-39141

  • libxstream-java Ubuntu 18.04 LTS 1.4.11.1-1+deb10u4build0.18.04.1
  • libxstream-java Ubuntu 20.04 LTS 1.4.11.1-1ubuntu0.3

ubuntu advisories UBUNTU-CVE-2021-39141

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • xstream RHEL 7 1.3.1-16.el7_9
  • xstream-javadoc RHEL 7 1.3.1-16.el7_9

red hat advisories RHSA-2021:3956

  • xstream SLE Module for Development Tools 15 SP3, SLE Module for Development Tools 15 SP2, Manager Server Module 4.2 +1 more 1.4.18-3.14.1

suse advisories SUSE-SU-2021:3476-1

  • xstream openSUSE Leap 15.2 1.4.18-lp152.2.12.1
  • xstream openSUSE Leap 15.3 1.4.18-3.14.1

opensuse advisories openSUSE-SU-2021:1401-1openSUSE-SU-2021:3476-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-39141 updated cvss 8.5

xstream: Arbitrary code execution via unsafe deserialization of com.sun.xml.internal.ws.client.sei.*

  • Red Hat BPM Suite 6 xstream Red Hat JBoss A-MQ 6 xstream Red Hat JBoss BRMS 5 xstream Red Hat JBoss BRMS 6 xstream Red Hat JBoss Data Grid 7 xstream Red Hat JBoss Data Virtualization 6 xstream
    +3 more products
    Red Hat JBoss Fuse 6 xstream Red Hat JBoss Fuse Service Works 6 xstream Red Hat JBoss SOA Platform 5 xstream
    affected: no fix planned “Out of support scope”
  • Red Hat Data Grid 8.3.0
    fixed: vendor fix RHSA-2022:0520
  • Red Hat Enterprise Linux Client Optional (v. 7) xstream 1.3.1-16.el7_9, xstream-javadoc 1.3.1-16.el7_9 Red Hat Enterprise Linux ComputeNode Optional (v. 7) xstream 1.3.1-16.el7_9, xstream-javadoc 1.3.1-16.el7_9 Red Hat Enterprise Linux Server Optional (v. 7) xstream 1.3.1-16.el7_9, xstream-javadoc 1.3.1-16.el7_9 Red Hat Enterprise Linux Workstation Optional (v. 7) xstream 1.3.1-16.el7_9, xstream-javadoc 1.3.1-16.el7_9
    fixed: vendor fix RHSA-2021:3956
  • Red Hat Integration
    fixed: vendor fix RHSA-2021:4918
  • Red Hat Integration Camel Quarkus 2
    fixed: vendor fix RHSA-2021:4767
  • Red Hat RHDM 7.12.0
    fixed: vendor fix RHSA-2022:0297
  • Red Hat RHPAM 7.12.0
    fixed: vendor fix RHSA-2022:0296
  • Red Hat Fuse 7 xstream Red Hat Integration Camel Quarkus 1 xstream Red Hat OpenShift Container Platform 3.11 jenkins Red Hat OpenShift Container Platform 4 jenkins
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
total
Assessed
32 d ago

Exploit prediction

16.12% chance of exploitation in the next 30 days, higher than 96% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Nuclei template XStream 1.4.18 - Remote Code Execution nuclei detection template
  • x-stream.github.io https://x-stream.github.io/CVE-2021-39141.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD 3.1 8.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
NVD 2.0 6.0 AV:N/AC:M/Au:S/C:P/I:P/A:P
GitHub 3.1 8.5 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
maven com.thoughtworks.xstream:xstream
<1.4.18
1.4.18

Affected products

  • x-stream xstream

Classification

Weakness
  • CWE-434 Unrestricted Upload of File with Dangerous Type
  • CWE-502 Deserialization of Untrusted Data

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.